TreeMap Disk Visualizer is an open-source disk analysis and cleanup application for Windows and macOS, with a browser-based mode for Linux. It displays storage usage through interactive treemaps, charts, grids, and three-dimensional visualizations. Users can explore folders, identify large files, and investigate storage consumption. Duplicate detection finds identical files and similar images. Historical scans reveal storage growth, changes, and potential disk capacity problems. Application and game library views identify caches and unnecessary data. A cleanup cart previews selected files before moving them to the system Trash. Additional tools include scheduled scans, storage alerts, automated cleanup rules, and file offloading. Its local-first architecture operates without telemetry or cloud processing.